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United States Patent | 6,205,338 |
Kim | March 20, 2001 |
An intercommunication method between portable units in a TDMA (Time Division Multiple Access) cordless telephone system. In an embodiment of the present invention, it is determined whether a portable unit is positioned in the propagation area of a base unit upon an intercom request from the portable unit. A time reversal is then performed when the portable unit is out of the propagation area of the base unit. Time slots are designated for intercommunication between the portable unit and a portable unit to be called and an intercom call signal is transmitted in the designated time slots. When a called party responds to the intercom call signal, a speech mode is performed. Upon termination of the intercom call, the reversed time is reversed again to recover the original state. In another embodiment, it is determined whether a portable unit is positioned in the propagation area of a base unit upon an intercom request from the portable unit. Time slots are designated for intercommunication between the portable unit and a portable unit to be called when the portable unit is out of the propagation area of the base unit, and an intercom call signal is transmitted in the designated time slots. When a called party responds to the intercom call signal, the speech mode is performed.
Inventors: | Kim; Ju-Nyun (Kyongsangbuk-do, KR) |
Assignee: | Samsung Electronics Co., Ltd. (KR) |
Appl. No.: | 134011 |
Filed: | August 14, 1998 |
Aug 14, 1997[KR] | 97/38835 |
Current U.S. Class: | 455/462; 455/465; 455/518 |
Intern'l Class: | H04Q 007/20; 450 |
Field of Search: | 455/421,422,426,433,434,435,436,440,444,456,457,462,465,518,519,513,423,11.1 370/282,347 |
4965849 | Oct., 1990 | Kunihiro | 455/463. |
5058151 | Oct., 1991 | Tanaka et al. | 455/462. |
5371783 | Dec., 1994 | Rose et al. | 455/462. |
5517551 | May., 1996 | Arai | 455/575. |
5812951 | Sep., 1998 | Ganesan et al. | 455/445. |
5911120 | Jun., 1999 | Jarett et al. | 455/417. |
5940766 | Aug., 1999 | Uratani | 455/465. |
5987318 | Nov., 1999 | Alperovich et al. | 455/416. |
6044268 | Mar., 2000 | Haartsen | 455/426. |
6052407 | Apr., 2000 | Ciccone et al. | 375/202. |
6052565 | Apr., 2000 | Ishikura et al. | 455/423. |
TABLE 1 portable registration unit unique code number CP_1 157 D77 CA 01 CP_2 157 CA3 30 02 CP_3 155 FF6 88 03 CP_4 156 BCC 65 04